Comparative proteomic analysis reveals sex and estrogen receptor β effects in the pressure overloaded heart.

In pressure overload (PO), sex differences in humans and rodents have been well documented and estrogen receptor (ER) β is considered cardioprotective. However, the underlying mechanisms are poorly understood. Our aim was to investigate sex- and ERβ-specific effects in protein abundance in PO employing a 2-dimensional gel electrophoresis/mass spectrometry-based proteomics approach.

MALDI imaging mass spectrometry: discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures.

Due to formation of fibrosis and the loss of contractile muscle tissue, severe muscle injuries often result in insufficient healing marked by a significant reduction of muscle force and motor activity. Our previous studies demonstrated that the local transplantation of mesenchymal stromal cells into an injured skeletal muscle of the rat improves the functional outcome of the healing process. Since, due to the lack of sufficient markers, the accurate discrimination of pathophysiological regions in injured skeletal muscle is inadequate, underlying mechanisms of the beneficial effects of mesenchymal stromal cell transplantation on primary trauma and trauma adjacent muscle area remain elusive.

Individualized proteomics.

Human individuals differ from one another in almost all of their genes due to single nucleotide polymorphisms (SNPs). When the maternal and the paternal genomes become combined in a F1 individual, the two alleles of each gene represent arbitrary combinations. In consequence, individuals show high variability in protein expression.

Application of two-dimensional gel-based mass spectrometry to functionally dissect resistance to targeted cancer therapy.

Purpose: The majority of gastric cancers are diagnosed at advanced stages, characterized by robust therapy resistance. The oncoprotein hypoxia-inducible factor 1 (HIF-1) is associated with therapy resistance, partly via activation of the DNA damage response. We have noted a robust ability of gastric cancer cells to functionally compensate the loss of HIF-1 in vitro.

SORLA-mediated trafficking of TrkB enhances the response of neurons to BDNF.

Stimulation of neurons with brain-derived neurotrophic factor (BDNF) results in robust induction of SORLA, an intracellular sorting receptor of the VPS10P domain receptor gene family. However, the relevance of SORLA for BDNF-induced neuronal responses has not previously been investigated. We now demonstrate that SORLA is a sorting factor for the tropomyosin-related kinase receptor B (TrkB) that facilitates trafficking of this BDNF receptor between synaptic plasma membranes, post-synaptic densities, and cell soma, a step critical for neuronal signal transduction.

Soluble alpha-APP (sAPPalpha) regulates CDK5 expression and activity in neurons.

A growing body of evidence suggests a role for soluble alpha-amyloid precursor protein (sAPPalpha) in pathomechanisms of Alzheimer disease (AD). This cleavage product of APP was identified to have neurotrophic properties. However, it remained enigmatic what proteins, targeted by sAPPalpha, might be involved in such neuroprotective actions.

Identification of fibronectin as a major factor in human serum to recruit subchondral mesenchymal progenitor cells.

Human serum has the potential for mesenchymal progenitor cell recruitment in repair of articular cartilage lesions. It is unclear which factor(s) in serum mediate this migratory effect. Our goal was to identify cell recruiting factors in human serum fractions obtained by ion exchange chromatography.

Quantitative and qualitative 2D electrophoretic analysis of differentially expressed mitochondrial proteins from five mouse organs.

Mitochondria fulfill many tissue-specific functions in cell metabolism. We set out to identify differences in the protein composition of mitochondria from five tissues frequently affected by mitochondrial disorders. The proteome of highly purified mitochondria from five mouse organs was separated by high-resolution 2DE.

Presymptomatic alterations in energy metabolism and oxidative stress in the APP23 mouse model of Alzheimer disease.

Glucose hypometabolism is the earliest symptom observed in the brains of Alzheimer disease (AD) patients. In a former study, we analyzed the cortical proteome of the APP23 mouse model of AD at presymptomatic age (1 month) using a 2-D electrophoresis-based approach. Interestingly, long before amyloidosis can be observed in APP23 mice, proteins associated with energy metabolism were predominantly altered in transgenic as compared to wild-type mice indicating presymptomatic changes in energy metabolism.

Mesenchymal stromal cells rescue cortical neurons from apoptotic cell death in an in vitro model of cerebral ischemia.

Cell therapy with mesenchymal stromal cells (MSCs) was found to protect neurons from damage after experimental stroke and is currently under investigation in clinical stroke trials. In order to elucidate the mechanisms of MSC-induced neuroprotection, we used the in vitro oxygen–glucose deprivation (OGD) model of cerebral ischemia. Co-culture of primary cortical neurons with MSCs in a transwell co-culture system for 48 h prior to OGD-reduced neuronal cell death by 30-35%.

Brain region specific mitophagy capacity could contribute to selective neuronal vulnerability in Parkinson's disease.

Parkinson's disease (PD) is histologically well defined by its characteristic degeneration of dopaminergic neurons in the substantia nigra pars compacta. Remarkably, divergent PD-related mutations can generate comparable brain region specific pathologies. This indicates that some intrinsic region-specificity respecting differential neuron vulnerability exists, which codetermines the disease progression.

Kainate promotes alterations in neuronal RNA splicing machinery.

Kainate, a glutamate analogue, activates kainate and AMPA receptors inducing strong synaptic activation. Systemic kainate application to rodents results in seizures, neurodegeneration, and neuronal remodeling in the brain. It is therefore used to investigate molecular mechanisms responsible for these conditions.

Proteasome and oxidative phoshorylation changes may explain why aging is a risk factor for neurodegenerative disorders.

Neurodegenerative disorders (ND) belong to the most devastating diseases in the industrialized western world. Alzheimer disease (AD) is the most prevalent among these disorders followed by Parkinson disease (PD). Huntington disease (HD) is an autosomal dominantly inherited condition with a single mutation that causes disease in almost 100% of all cases.

A mouse embryonic stem cell bank for inducible overexpression of human chromosome 21 genes.

Background: Dosage imbalance is responsible for several genetic diseases, among which Down syndrome is caused by the trisomy of human chromosome 21.

Results: To elucidate the extent to which the dosage imbalance of specific human chromosome 21 genes perturb distinct molecular pathways, we developed the first mouse embryonic stem (ES) cell bank of human chromosome 21 genes. The human chromosome 21-mouse ES cell bank includes, in triplicate clones, 32 human chromosome 21 genes, which can be overexpressed in an inducible manner.

Establishment of a mouse model with misregulated chromosome condensation due to defective Mcph1 function.

Mutations in the human gene MCPH1 cause primary microcephaly associated with a unique cellular phenotype with premature chromosome condensation (PCC) in early G2 phase and delayed decondensation post-mitosis (PCC syndrome). The gene encodes the BRCT-domain containing protein microcephalin/BRIT1. Apart from its role in the regulation of chromosome condensation, the protein is involved in the cellular response to DNA damage.

From 2-D electrophoresis to proteomics.

At first, a short history of the beginning of 2-DE is provided. Based on the present state of the art at the time I developed a 2-DE technique in 1975 that was able to resolve complex protein extracts from mouse tissues in hundreds of protein spots. My intention was to study proteins from a global point of view.

Insights into mesenchymal stem cell aging: involvement of antioxidant defense and actin cytoskeleton.

Progenitor cells such as mesenchymal stem cells (MSCs) have elicited great hopes for therapeutic augmentation of physiological regeneration processes, e.g., for bone fracture healing.

A systematic proteomic study of irradiated DNA repair deficient Nbn-mice.

Background: The NBN gene codes for the protein nibrin, which is involved in the detection and repair of DNA double strand breaks (DSBs). The NBN gene is essential in mammals.

Methodology/principal Findings: We have used a conditional null mutant mouse model in a proteomics approach to identify proteins with modified expression levels after 4 Gy ionizing irradiation in the absence of nibrin in vivo.

High-resolution large-gel 2DE.

Our two-dimensional gel electrophoresis (2DE) protocol has been continuously improved in our laboratory since its inception 30 years ago. An updated version is presented here. This protocol is a result of our experience in proteome analysis of tissue extracts, cultured cells (mammalian, yeast, and bacteria), cellular organelles, and subcellular fractions.

Protein extraction for 2DE.

Our protein extraction protocol for two-dimensional gel electrophoresis (2DE) was updated to meet current needs in the field of proteomics. This protocol summarizes our experience using this method since its introduction over 30 years ago. We provide a total as well as fractionated extraction protocol.

PROTEOMER: A workflow-optimized laboratory information management system for 2-D electrophoresis-centered proteomics.

In recent years proteomics became increasingly important to functional genomics. Although a large amount of data is generated by high throughput large-scale techniques, a connection of these mostly heterogeneous data from different analytical platforms and of different experiments is limited. Data mining procedures and algorithms are often insufficient to extract meaningful results from large datasets and therefore limit the exploitation of the generated biological information.

Mutant Hoxd13 induces extra digits in a mouse model of synpolydactyly directly and by decreasing retinoic acid synthesis.

Individuals with the birth defect synpolydactyly (SPD) have 1 or more digit duplicated and 2 or more digits fused together. One form of SPD is caused by polyalanine expansions in homeobox d13 (Hoxd13). Here we have used the naturally occurring mouse mutant that has the same mutation, the SPD homolog (Spdh) allele, and a similar phenotype, to investigate the molecular pathogenesis of SPD.